Organic EL device

ABSTRACT

According to one embodiment, an organic EL device includes an insulating substrate including a first main surface and a second main surface, a switching element formed on the insulating substrate at the first main surface side, a first electrode electrically connected to the switching element, a second electrode opposed to the first electrode, an organic luminescent layer disposed between the first electrode and the second electrode, a reflective plate disposed between the insulating substrate and the first electrode, and a conductive film covering the second main surface of the insulating substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/708,597 filed May 11, 2015, and is based upon and claims the benefitof priority from Japanese Patent Application No. 2014-099524, filed May13, 2014, the entire contents of each of which are incorporated hereinby reference.

FIELD

Embodiments described herein relate generally to an organic EL deviceand a manufacturing method of the same.

BACKGROUND

In a manufacturing process of display devices such as a liquid crystaldisplay device and an organic electroluminescence (EL) display device,an electrostatic charge which occurs during the manufacturing processmay cause destruction of the device. To prevent the destruction, variouscountermeasures are adopted. As an example of such a countermeasure,there is a known technique to form a transparent conductive film on arear surface of an insulating substrate, that is, on a surface opposedto a surface on which a thin-film transistor or the like are formed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows the structure of an organic EL device 1 of anembodiment.

FIG. 2 is a cross-sectional view which schematically shows a structuralexample of an array substrate AR which is applicable to the organic ELdevice 1 in FIG. 1.

FIG. 3 shows a manufacturing method of the organic EL device 1 and showsthat a conductive film CD is interposed between a supporting substrate100 and a mother substrate 110.

FIG. 4 shows the manufacturing method of the organic EL device 1 andshows a process of forming display element units 121 to 123 and mountunits 131 to 133.

FIG. 5 shows the manufacturing method of the organic EL device 1 andshows a process of dividing the mother substrate 110.

FIG. 6 shows the manufacturing method of the organic EL device 1 andshows a process of mounting a signal supplier 300 on the mount unit 131.

FIG. 7 shows the manufacturing method of the organic EL device 1 andshows a process of removing the supporting substrate 100 from the mothersubstrate 110.

FIG. 8 shows another manufacturing method of the organic EL device 1 andshows a process of disposing a mother substrate 110 on a supportingsubstrate 100 which is covered with a conductive film.

FIG. 9 shows another manufacturing method of the organic EL device 1 andshows a process of preparing the mother substrate 110 which is coveredwith the conductive film.

FIG. 10 shown another manufacturing method of the organic EL device 1and shows a process of forming display element units 121 to 123 andmount units 131 to 133.

FIG. 11 shows still another manufacturing method of the organic ELdevice 1 and shows a process of polishing the mother substrate 110.

FIG. 12 schematically shows another structural example of the organic ELdevice 1 of the present embodiment.

DETAILED DESCRIPTION

In general, according to one embodiment, an organic EL device comprises:an insulating substrate including a first main surface and a second mainsurface; a switching element formed on the insulating substrate at thefirst main surface side; a first electrode electrically connected to theswitching element; a second electrode opposed to the first electrode; anorganic luminescence layer disposed between the first electrode and thesecond electrode; a reflective plate disposed between the insulatingsubstrate and the first electrode; and a conductive film covering thesecond main surface of the insulating substrate.

According to another embodiment, a manufacturing method of an organic ELdevice comprises: disposing a mother substrate on a supporting substratewith a conductive film interposed therebetween; forming a switchingelement, reflective plate, and display element unit on the mothersubstrate, the display element unit including an organic EL elementpositioned above the switching element and the reflective plate; andremoving the supporting substrate from the mother substrate.

Embodiments are described with reference to accompanying drawings. Notethat the disclosure is presented for the sake of exemplification, andany modification and variation conceived within the scope and spirit ofthe invention by a person having ordinary skill in the art are naturallyencompassed in the scope of invention of the present application.Furthermore, a width, thickness, shape, and the like of each element aredepicted schematically in the Figures as compared to actual embodimentsfor the sake of simpler explanation, and they are not to limit theinterpretation of the invention of the present application. Furthermore,in the description and Figures of the present application, structuralelements having the same or similar functions will be referred to by thesame reference numbers and detailed explanations of them that areconsidered redundant may be omitted.

In the present embodiment, an organic electroluminescence (EL) device isan organic EL display device. However, no limitation is intendedthereby, and the organic EL device may be an organic EL illuminationdevice or an organic EL printer head, for example.

FIG. 1 schematically shows the structure of an organic EL device 1 ofthe present embodiment. Note that only the main parts of the structurewhich are necessary for the explanation are depicted therein.

That is, the organic EL device 1 includes a substantially rectangularflat-panel display panel PNL, and a driving IC chip 2 and a flexibleprinted circuit board 3 connected to the display panel PNL.

The display panel PNL includes an array substrate AR and acounter-substrate CT opposed to the array substrate AR. Between thearray substrate AR and the counter-substrate CT, a filler may bedisposed, or an evacuated space or a space filled with inert gas may beformed. As described later, the array substrate AR includes an organicEL element and the like. Furthermore, the array substrate AR includes aconductive film CD on its rear surface ARA, that is, on a surfaceopposed to the surface facing the counter-substrate CT. Thecounter-substrate CT may be a shield substrate which shields the organicEL element or may be a cover glass of an electronic device with theorganic EL device 1 incorporated. The organic EL device 1 may include atouch-panel which detects contact or approach of an object to thesurface of the cover glass.

The display panel PNL includes an active area ACT which displays images.The active area ACT is formed in, for example, a quadrangle and iscomposed of a plurality of pixels PX arranged in an m×n matrix (m and nare a positive integer). Each pixel PX may be composed of threesub-pixels of red, green, and blue, or may be composed of foursub-pixels of red, green, blue, and, for example, white. Each sub-pixelincludes an organic EL element.

The driving IC chip 2 and the flexible printed circuit board 3 aremounted on the array substrate AR outside the active area ACT andfunction as signal suppliers which supply signals necessary for drive ofthe pixels PX.

FIG. 2 is a cross-sectional view which schematically shows a structuralexample of the array substrate AR which is applicable to the organic ELdevice 1 shown in FIG. 1.

The array substrate AR may be formed of a first insulating substrate 10.The first insulating substrate 10 may be glass substrate or resinsubstrate. The resin substrate is formed of, for example, polyimide,polyethylene terephthalate, polyethylene naphthalate, polycarbonate, andpolyether sulfone. The first insulating substrate 10 has a first mainsurface (inner surface) 10A and a second main surface (outer surface)10B. The second main surface 10B corresponds to the rear surface ARA ofthe array substrate AR.

The array substrate AR includes, at the first main surface 10A side ofthe first insulating substrate 10, a first insulating film 11, a secondinsulating film 12, a third insulating film 13, a fourth insulating film14, a bank 15, switching elements SW1 to SW3, a reflective plate RP,organic EL elements OLED1 to OLED3, and a sealing film 20. Furthermore,the array substrate AR includes a conductive film CD at the second mainsurface 10B side of the first insulating substrate 10.

The first main surface 10A of the first insulating substrate 10 iscovered with the first insulating film 11. The first insulating film 11is formed of an inorganic material such as silicon nitride (SiN),silicon oxide (SiO), and silicon oxynitride (SiON), and is a monolayeror a multilayer.

The switching elements SW1 to SW3 are formed on the first insulatingfilm 11. The switching element SW1 is disposed on the blue pixel PXB,the switching element SW2 is disposed on the green pixel PXG, and theswitching element SW3 is disposed on the red pixel PXR. Each ofswitching elements SW1 to SW3 is, for example, a thin-film transistor(TFT) including a semiconductor layer SC. The switching elements SW1 toSW3 are structured the same, and in the following description, theswitching element SW1 is focused to explain its detailed structure.

In the example depicted, the switching element SW1 is of the top-gatetype and includes a semiconductor layer SC formed of polycrystallinesilicon (p-Si). Note that the semiconductor layer SC may be formed ofamorphous silicon (a-Si) or oxide semiconductor. The switching elementSW1 may be of the bottom-gate type. Here, a top-gate thin-filmtransistor usable as a switching element can reduce the parasiticcapacitance better as compared to a bottom-gate thin-film transistor,and thus is more suitable.

The semiconductor layer SC includes a channel region SCC, and a firstimpurity region SC1 and a second impurity region SC2 containing moreimpurities than the channel region SCC. The channel region SCC isdisposed between the first impurity region SC1 and the second impurityregion SC2. Furthermore, the channel region SCC is a region whoseresistance is higher than that of the first impurity region SC1 and thesecond impurity region SC2. The semiconductor layer SC is formed on thefirst insulating film 11 and is covered with the second insulating film12. The second insulating film 12 is disposed on the first insulatingfilm 11. Such a second insulating film 12 is formed of an inorganicmaterial such as silicon oxide.

A gate electrode WG of the witching element SW1 is formed on the secondinsulating film 12 and is disposed immediately above the channel regionSCC. The gate electrode WG is formed of a metal such as molybdenum (Mo),tungsten (W), aluminum (Al), titanium (Ti), and copper (Cu), or of analloy containing these metals. In this example, the gate electrode WG isformed of molybdenum tungsten (MoW). The gate electrode WG is coveredwith the third insulating film 13. The third insulating film 13 isdisposed on the second insulating film 12. The third insulating film 13is formed of an inorganic material such as silicon nitride or siliconoxide.

The first electrode WE1 and the second electrode WE2 of the switchingelement SW1 are formed on the third insulating film 13. The firstelectrode WE1 is electrically connected to the first impurity region SC1of the semiconductor layer SC, and the second electrode WE2 iselectrically connected to the second impurity region SC2 of thesemiconductor layer SC. The first electrode WE1 and the second electrodeWE2 are formed of a metal such as molybdenum (Mo), tungsten (W),aluminum (Al), titanium (Ti), and copper (Cu) or of an alloy containingthese metals. In this example, the first electrode WE1 and the secondelectrode WE2 are formed of a multilayer of aluminum and titanium. Thefirst electrode WE1 and the second electrode WE2 are covered with thefourth insulating film 14. The fourth insulating film 14 is disposed onthe third insulating film 13. The fourth insulating film 14 is formed ofa resin material such as acrylic resin.

The organic EL elements OLED1 to OLED3 are formed on the fourthinsulating film 14. The organic EL element OLED1 is disposed on a bluepixel PXB and is electrically connected to the switching element SW1.The organic EL element OLED2 is disposed on a green pixel PXG and iselectrically connected to the switching element SW2. The organic ELelement OLED3 is disposed on a red pixel PXR and is electricallyconnected to the switching element SW3. Each of the organic EL elementsOLED1 to OLED3 are self-luminescent element of the top-emission typewhich emits light toward the sealing film 20 side, and emits light ofdifferent colors.

The banks 15 are formed on the fourth insulating film 14 to define theorganic EL elements OLED1 to OLED3. Note that, although this is notdescribed in detail, the banks 15 are formed on the fourth insulatingfilm 14 in a lattice or stripes, for example.

The organic EL element OLED1 includes a pixel electrode (firstelectrode) PE1, a common electrode (second electrode) CE opposed to thepixel electrode PE1, and an organic luminescent layer ORG(B) disposedbetween the pixel electrode PE1 and the common electrode CE. The organicEL element OLED2 includes a pixel electrode PE2, the common electrode CEopposed to the pixel electrode PE2, and an organic luminescent layerORG(G) disposed between the pixel electrode PE2 and the common electrodeCE. The organic EL element OLED3 includes a pixel electrode PE3, thecommon electrode CE opposed to the pixel electrode PE3, and an organicluminescent layer ORG(R) disposed between the pixel electrode PE3 andthe common electrode CE.

The pixel electrode PE1 is electrically connected to the switchingelement SW1. The pixel electrode PE2 is electrically connected to theswitching element SW2. The pixel electrode PE3 is electrically connectedto the switching element SW3. Each edge of the pixel electrodes PE1 toPE3 is covered with the bank 15. The pixel electrodes PE1 to PE3 areformed of a transparent material such as indium tin oxide (ITO) andindium zinc oxide (IZO).

The reflective plate RP is disposed between the first insulatingsubstrate 10 and the pixel electrodes PE1 to PE3. In the exampledepicted, the reflective plates RP are formed in islands on the fourthinsulating film 14 to overlap the pixel electrodes PE1 to PE3,individually. The reflective plate RP is formed of a highly reflectivemetal such as aluminum (Al), magnesium (Mg), silver (Ag), and titanium(Ti). Note that the reflective plates RP may be disposed at any positionbetween the first insulating substrate 10 and the pixel electrodes PE1to PE3. However, in consideration of the emitting light from the organicEL elements OLED1 to OLED3 reaching the switching elements SW1 to SW3which causes a malfunction of the switching elements SW1 to SW3 and thelike, the reflective plates RP should preferably be disposed to becloser to the pixel electrodes PE1 to PE3. For example, the reflectiveplates RP should preferably be disposed between the switching elementsSW1 to SW3 and the pixel electrodes PE1 to PE3, or may be disposed tocover the switching elements SW1 to SW3.

The organic luminescent layer ORG(B) contains a dopant material whichemits blue light. The organic luminescent layer ORG(G) contains a dopantmaterial which emits green light. The organic luminescent layer ORG(R)contains a dopant material which emits red light. The organicluminescent layers ORG(B), ORG(G), and ORG(R) break off by the banks 15.

The common electrode CE is formed continuously over the organic ELelements OLED1 to OLED3 without a break, and covers the banks 15 exposedfrom the organic luminescent layers. The common electrode CE is formedof a transparent conductive material such as ITO and IZO. The commonelectrode CE may be a semitransparent film formed of magnesium (Mg) andsilver (Ag), instead.

Note that, in organic EL elements OLED1 to OLED3, a hole injection layeror a hole transportation layer may additionally be interposed betweenthe pixel electrode PE1 to PE3 and the organic luminescent layersORG(B), ORG(G), and ORG(R). Furthermore, an electron injection layer andan electron transportation layer may additionally be interposed betweenthe organic luminescent layers ORG(B), ORG(G), and ORG(R) and the commonelectrode CE.

The sealing film 20 seals the organic EL elements OLED1 to OLED3. Thesealing film 20 protects the organic EL elements OLED1 to OLED3 frommoisture and oxygen. The sealing film 20 is formed of a transparent andhighly water-resistant material. For example, the sealing film 20 is amultilayer of inorganic thin films formed of an inorganic material andorganic thin films formed of an organic material layered one afteranother.

The conductive film CD covers the rear surface of the array substrateAR, that is, the second main surface 10B of the first insulatingsubstrate 10. The conductive film CD may be formed of various kinds ofmetals, metal compounds, alloys, conductive organic materials, ortransparent conductive materials such as ITO. For example, theconductive film CD may be formed of a material containing ahigh-melting-point metal. Specifically, the conductive film CD can beformed of a high-melting-point metal nitride or a high-melting-pointmetal oxide. The high-melting-point metal may be tungsten, tantalum,molybdenum, or niobium, or an alloy containing these elements. Theconductive film CD formed of a material containing a high-melting-pointmetal can prevent its deformation and melting during a manufacturingprocess performed in a high temperature environment. Note that, ingeneral, nitride possesses better conductivity as compared to oxide.Furthermore, since oxide easily reacts with a gas such as hydrogen, itwould affect manufacturing process of the array substrate AR in variousways. From these standpoints, the conductive film CD should preferablybe formed of a high-melting-point metal nitride.

According to the organic EL device 1 as above, when each of organic ELelements OLED1 to OLED3 emits light, the light emitted therefrom travelsoutward passing through the sealing film 20. From the blue pixel PXB,the organic EL element OLED1 emits blue light. From the green pixel PXG,the organic EL element OLED2 emits green light. From the red pixel PXR,the organic EL element OLED3 emits red light. Therefore, color displayis achieved.

Note that the structure of the array substrate AR is not limited to theexample described above. For example, if the pixel PX additionallyincludes a white Sub-pixel, the white sub-pixel may include an organicEL element having an organic luminescent layer which emits white light,or may include the organic EL elements OLED1 to OLED3 described above.

Furthermore, as the array substrate AR, an organic luminescent layerformed continuously over the organic EL elements OLED1 to OLED3 withouta break and emitting white light can be adopted. If such an arraysubstrate AR is adopted, the color filters opposed to the organic ELelements OLED1 to OLED3 are used to achieve the color display.

Now, the manufacturing method of the organic EL element 1 is explainedwith reference to FIGS. 3 to 7.

Initially, as shown in FIG. 3, a mother substrate 110 is disposed on asupporting substrate 100 with the conductive film CD interposedtherebetween. The supporting substrate 100 is glass substrate, forexample. The mother substrate 110 corresponds to the first insulatingsubstrate 10, and may be glass substrate or resin substrate. Theconductive film CD is formed on the main surface 110B of the mothersubstrate 110, or may be formed on the main surface 100A of thesupporting substrate 100, or may be sandwiched between the supportingsubstrate 100 and the mother substrate 110. Specific materials for theconductive film CD are exemplified above.

Then, as shown in FIG. 4, display element units 121 to 123 are formed onthe main surface 110A of the mother substrate 110. For example, adisplay element unit 121 is formed in a first area A1 on the mothersubstrate 110, a display element unit 122 is formed in a second area A2on the mother substrate 110, and a display element unit 123 is formed ina third area A3 on the mother substrate 110. Through the process to formthe display element units 121 to 123, mount units 131 to 133 are alsoformed on the mother substrate 110. The first area A1, second area A2,and third area A3 are apart from each other, and they correspond to theactive areas in the chips formed after dividing the mother substrate110. The display element units 121 to 123 have the same structure andeach include a plurality of organic EL elements arranged in a matrix.Furthermore, the mount units 131 to 133 have the same structure andinclude a plurality of pads on which signal suppliers such as thedriving IC chip 2 and the flexible printed circuit board 3 are mountedlater.

Each of the display element units 121 to 123 is structured as shown inFIG. 2. In this example, the display element units 121 to 123 are formedin the following manner. That is, the first insulating film 11 is formedon the mother substrate 110, and then, the switching elements SW1 toSW3, the second insulating film 12, the third insulating film 13, andthe fourth insulating film 14 are formed above the first insulating film11. In the process of forming these switching elements SW1 to SW3,various wirings are formed concurrently. Then, the reflective plate RPis formed on the fourth insulating film 14, and the pixel electrodes PE1to PE3 of the organic EL elements OLED1 to OLED3, the banks 15, theorganic luminescent layers ORG of the organic EL elements OLED1 toOLED3, the common electrode CE, and the sealing film 20 are formedsequentially. After that, the counter-substrate may be adhered to thedisplay element units 121 to 123; however, the explanation ofcounter-substrate is irrelevant and thus omitted.

Note that the organic luminescent layers ORG(B), ORG(G), and ORG(R) canbe formed individually through the following process. That is, if theorganic luminescent layers are formed of a polymeric material, an inkjetprocess or the like is applicable. Or, if the organic luminescent layersare formed of a low molecular material, a vapor deposition process orthe like is applicable.

Then, as shown in FIG. 5, the mother substrate 110 is divided. In theexample depicted, the mother substrate 110 is divided along with thesupporting substrate 100 at the position between the mount unit 131 andthe display element unit 122, and the position between the mount unit132 and the display element unit 123. Especially, if the mothersubstrate 110 is resin substrate or very thin glass substrate, themother substrate 110 and the supporting substrate 100 should preferablybe formed integrally to easily handle the mother substrate 110. Thoughthe above, a chip C1 including the display element unit 121 and themount unit 131, a chip C2 including the display element unit 122 and themount unit 132, and a chip C3 including the display element unit 123 andthe mount unit 133 are formed individually.

Then, as shown in FIG. 6, a signal supplier 300 is mounted on the mountunit 131 of the chip C1. At that time, the chip C1 can be sufficientlysupported by the remaining supporting substrate 100 against the pressureforce applied when the signal supplier 300 is mounted. Note that,although this is not described in detail, signal suppliers are mountedon the mount unit 132 of the chip C2 and on the mount unit 133 of thechip C3 in a similar manner.

Then, as shown in FIG. 7, the supporting substrate 100 is removed fromthe mother substrate 110 with respect to the chip C1 shown in FIG. 6. Ifthe mother substrate 110 is fixed to the supporting substrate 100 in thepreceding manufacturing process, the supporting substrate 100 may beremoved from the mother substrate 110 by a laser ablation process or athermal rapid annealing process; however, the process is not limitedthereto. In the example depicted, the main surface 110B of the mothersubstrate 110 from which the supporting substrate 100 has been removedis covered with the conductive film CD. Consequently, the organic ELdevice 1 structured as in FIGS. 1 and 2 can be manufactured. Similarly,the supporting substrates 100 are removed from the mother substrates 110of the other chips C2 and C3.

In the manufacturing process explained above, electrostatic energy iseasily generated because of a contact, friction, and exfoliation betweenthe mother substrate and various manufacturing apparatuses and conveyingmechanisms or because of a plasma process such as plasma CVD. Ifelectrostatic energy is charged locally on the mother substrate,electrostatic destruction tends to occur in the switching elements andvarious wirings. In recent years, the organic EL devices are designed tobe more miniaturized and minute, and various circuits including theswitching element become smaller and various wirings become narrower.Such miniaturized circuits and wirings are easily destroyed by theelectrostatic charge acting thereon because of their small capacitance.

In the present embodiment, even if electrostatic energy is generated inthe manufacturing process of the organic EL device 1, the conductivefilm CD contacting the mother substrate 110 diffuses the electrostaticenergy. Therefore, electrostatic energy is not charged locally on themother substrate 110 during the manufacturing process and electrostaticdestruction of various circuits and various wirings can be prevented.Therefore, decrease in the productivity can be suppressed.

Furthermore, the conductive film CD covers the second main surface 10Bof the first insulating substrate 10 cut out by the dividing process ofthe mother substrate 110. Therefore, the organic EL device 1manufactured as above transmits and diffuses the heat from the arraysubstrate AR to the conductive film CD, and thus, radiation performanceof the array substrate AR can be improved.

Furthermore, the organic EL element OLED formed on the first mainsurface 10A side of the first insulating substrate 10 is of thetop-emission type which includes the reflective plate RP at the firstinsulating substrate 10 side. Therefore, as compared to a structurewhich includes no reflective plate except a conductive film CD coveringthe second main surface 10B of the first insulating substrate 10 as areflective plate, the light emitted from the organic EL element OLED canbe reflected by the reflective plate RP to suppress the light reachingthe switching elements. Consequently, an erroneous reaction of theswitching element caused by the emitted light can be suppressed.

Furthermore, since the conductive film CD covering the second mainsurface 10B of the first insulating substrate 10 is formed of a lowerpermeable material, the infiltration of moisture into the firstinsulating substrate 10 can be suppressed even if the first insulatingsubstrate 10 is formed of a resin material, and deterioration of theorganic EL element OLED caused by moisture can be reduced.

Note that, in the process of removing the supporting substrate 100 fromthe mother substrate 110 explained with reference to FIG. 7, the exampleis given that the main surface 110B of the mother substrate 110 iscovered with the conductive film CD; however, the conductive film CD maybe removed from the mother substrate 110 along with the supportingsubstrate 100. In that case, the organic EL device 1 as manufactureddoes not include a conductive film CD. However, the conductive film CDis still interposed between the supporting substrate 100 and the mothersubstrate 110 in the manufacturing process of the organic EL device 1,and the electrostatic energy that occurs in the manufacturing process isdiffused by the conductive film CD. Therefore, as in the manufacturingmethod described above, electrostatic destruction of various circuitsand various wirings can be suppressed and the decrease in productivitycan be suppressed, too.

Now, another manufacturing method of the organic EL device 1 isexplained.

The example depicted in FIG. 8 differs from the example depicted in FIG.3 in that the main surface 100B of the supporting substrate 100 iscovered with the conductive film CD and that the mother substrate 110 isdisposed on the main surface 100A of the supporting substrate 100. Thesupporting substrate 100 is, for example, glass substrate and the mothersubstrate 110 is either glass substrate or resin substrate.

A display element unit 121 is formed on a first area A1 on the mothersubstrate 110, a display element unit 122 is formed on a second area A2on the mother substrate 110, and a display element unit 123 is formed ona third area A3 on the mother substrate 110. Furthermore, through theformation of the display element units 121 to 123, the mount units 131to 133 are formed on the mother substrate 110 concurrently.

After this process, the processes depicted in FIGS. 5 to 7 areperformed.

The organic EL device 1 manufactured by the above method does notinclude a conductive film CD. However, since the main surface 100B ofthe supporting substrate 100 is covered with the conductive film CD inthe manufacturing process of the organic EL device 1, electrostaticenergy that occurs in the manufacturing process is diffused by theconductive film CD. Therefore, as in the manufacturing method describedabove, electrostatic destruction of various circuits and various wiringscan be suppressed and the decrease in productivity can be suppressed,too.

Now, still another manufacturing method of the organic EL device 1 isexplained.

The manufacturing method explained here uses relatively thick glasssubstrate as a mother substrate 110, and includes a process to polishthe mother substrate 110 later in the method.

As shown in FIG. 9, a mother substrate 110 whose main surface 110B iscovered with a conductive film CD is prepared first. The mothersubstrate 110 is glass substrate having a thickness T1 of 1 mm or less,for example. In this example, thickness T1 of the mother substrate 110is 0.5 mm.

Then, as shown in FIG. 10, display element units 121 to 123 and mountunits 131 to 133 are formed on the main surface 110A of the mothersubstrate 110. The display element units and mount units are formed asdepicted in FIG. 4.

Then, as shown in FIG. 11, the main surface 110B of the mother substrate110 is polished until the mother substrate 110 reaches a predeterminedthickness. In this example, the mother substrate 110 is polished bychemical etching. The chemical etching is performed using a hydrofluoricacid solution containing 10 wt % or more of hydrogen fluoride asetchant.

Specifically, the hydrofluoric acid solution erodes the conductive filmCD first and removes the conductive film CD, and then, the hydrofluoricacid solution erodes the mother substrate 110 from the main surface 110Bside until it reaches thickness T2. In this example, thickness T2 of themother substrate 110 after the polishing is set to approximately 0.15mm.

Then, as depicted in FIG. 5, the mother substrate 110 is divided into aplurality of chips, and as depicted in FIG. 6, a signal supplier ismounted on a mount unit in each chip. Consequently, the organic ELdevice 1 can be manufactured.

The organic EL device 1 manufactured by the above method does notinclude a conductive film CD. That is, the conductive film CD is removedin the polishing process of the mother substrate 110 with the displayelement units and the like formed thereon. In other words, theconductive film CD remains in the process to form the display elementunits and the like. Therefore, electrostatic energy that occurs in theprocess to form the display element units and the like is diffused bythe conductive film CD, and electrostatic destruction of variouscircuits and various wirings can be suppressed.

During the process to form the display element units and the like,electrostatic destruction occurs exceptionally when the electrodes andwirings formed in islands are in the floating state. That is, at thetime when the display element units and the like are formed, switchingelements are electrically connected to gate lines and source lines, andthus, electric charge tends to be dispersed. Furthermore, at the timewhen the display element units and the like are formed, short rings toprotect the display element units from electrostatic energy may beformed, and thus, electrostatic destruction scarcely occurs. Therefore,even if the conductive film CD is removed after the display elementunits and the like are formed, the decrease in the productivity causedby the electrostatic destruction can be suppressed.

Now, another structural example of the organic EL device 1 of thepresent embodiment is explained.

FIG. 12 schematically shows another structural example of the organic ELdevice 1 of the present embodiment.

The organic EL device 1 depicted here differs from that of the FIG. 1 inthat an insulating cover CV covering a conductive film CD.

Specifically, the insulating cover CV overlaps the conductive film CDfacing the rear surface ARA of the array substrate AR. In the exampledepicted, the insulating cover CV exposes four end surfaces of theconductive film CD; however, no limitation is intended thereby. That is,the insulating cover CV may covers the entire end surfaces of theconductive film CD. The insulating cover CV may be an inorganic thinfilm formed of an inorganic material or may be an organic thin filmformed of an organic thin film, or may be a multilayer of such inorganicand organic thin films.

The same advantages obtained from the above structural example can beachieved by this structural example. In addition, when the organic ELdevice 1 with the conductive film CD is incorporated in an electronicdevice, a short-circuit due to a contact between the conductive film CDand wirings and circuits in the electronic device can be prevented. Inrecent years, extremely thin electronic devices are trend. That is, asufficient gap between the organic EL device 1 and the wirings andcircuits of the electronic device is harder to secure when the organicEL device 1 is incorporated in the electronic device. However, thisstructure can prevent a short-circuit caused by the conductive film CDcontacting the internal components of the electronic device whilemaintaining the electronic device thin as required.

As can be understood from the above, the present embodiment can providean organic EL device which can suppress the decrease in productivity anda manufacturing method of the same.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. An organic EL device comprising: an arraysubstrate including: an insulating substrate including a first mainsurface and a second main surface, an organic luminescence layer on afirst main surface side of the insulating substrate, and a conductivefilm directly on the second main surface; a flexible printed circuitboard on the first main surface side of the insulating substrate; and adriving IC chip on the first main surface side of the insulatingsubstrate, wherein the conductive film is formed over an entirety of thearray substrate, the driving IC chip overlaps the conductive film, and acutting plane of the insulating substrate and a cutting plane of theconductive film are flush with one another.
 2. An organic EL devicecomprising: an array substrate including: an insulating substrateincluding a first main surface and a second main surface, an organicluminescence layer on a first main surface side of the insulatingsubstrate, and a conductive film directly on the second main surface; aflexible printed circuit board on the first main surface side of theinsulating substrate; and a driving IC chip on the first main surfaceside of the insulating substrate, wherein the conductive film is formedover an entirety of the array substrate, the driving IC chip overlapsthe conductive film, and the flexible printed circuit board overlaps theconductive film.
 3. An organic EL device comprising: an array substrateincluding: an insulating substrate including a first main surface and asecond main surface, an organic luminescence layer on a first mainsurface side of the insulating substrate, and a conductive film directlyon the second main surface; a flexible printed circuit board on thefirst main surface side of the insulating substrate; and an insulativecover, wherein the conductive film is formed over an entirety of thearray substrate, and the conductive film is sandwiched between theinsulating cover and the insulating substrate.
 4. The organic EL deviceof claim 2, further comprising an insulating cover, wherein theconductive film is sandwiched between the insulating cover and theinsulating substrate.
 5. The organic EL device of claim 1, wherein theconductive film is formed of a nitride.
 6. The organic EL device ofclaim 2, wherein the conductive film is formed of a nitride.
 7. Theorganic EL device of claim 1, wherein the conductive film is formed of ahigh-melting-point metal nitride.
 8. The organic EL device of claim 2,wherein the conductive film is formed of a high-melting-point metalnitride.
 9. The organic EL device of claim 1, wherein the insulatingsubstrate is formed of resin material.
 10. The organic EL device ofclaim 2, wherein the insulating substrate is formed of resin material.11. The organic EL device of claim 3, wherein the insulating coveroverlaps the flexible printed circuit board.
 12. The organic EL deviceof claim 4, wherein the insulating cover overlaps the flexible printedcircuit board.
 13. The organic EL device of claim 2, wherein a cuttingplane of the insulating substrate and a cutting plane of the conductivefilm are flush with one another.
 14. The organic EL device of claim 3,wherein a cutting plane of the insulating substrate and a cutting planeof the conductive film are flush with one another.
 15. The organic ELdevice of claim 14, wherein the insulating cover exposes the cuttingplane of the conductive film.
 16. The organic EL device of claim 1,further comprising an insulating cover, wherein the conductive film issandwiched between the insulating cover and the insulating substrate,and the insulating cover exposes the cutting plane of the conductivefilm.
 17. The organic EL device of claim 14, wherein the insulatingcover covers an entire of the cutting plane of the conductive film.